Page 255 - Like me, or else... - Michelle Achterberg

Summary and general discussion
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mechanism and is related to behavioral outcomes. However, these models specifically focused on adolescent brain development, whereas the findings of this thesis show that important changes in this neural network occur during childhood. Theoretical perspectives based on behavioral studies have suggested that the development of emotion regulation is closely related to the development of cognitive control (Diamond, 2013) and experimental studies have shown that cognitive control development accelerates during childhood (Luna et al., 2004; Zelazo and Carlson, 2012; Peters et al., 2016). The current thesis provides direct links between maturation of cognitive control (DLPFC) regions and individual differences in social emotion regulation. This was shown in a specific age range (7-9-year old to 9-11-year old), to provide a detailed analysis of changes in childhood. The results provide a window for understanding individual differences in these developmental trajectories, showing that some children develop better regulation skills already in childhood. Future research should examine developmental changes in a longer time window by including more measurement points, which allows disentangling general developmental patterns from individual differences in growth trajectories.
Childhood: A window of opportunity
As children grow older and move towards adolescents, they generally receive more autonomy and are less often under adult supervision (Steinberg et al., 1989). In some individuals this results in increased risk taking and sensation seeking, which can have negative consequences such as physical and psychological injury (Steinberg, 2008). To understand individual differences in these behaviors, several neurodevelopmental models have been proposed (see Casey (2015) for an overview), all of which focus on adolescent brain development. The longitudinal analyses across children, adolescents and adults in this thesis (chapter 8), however, showed that structural connectivity between the striatum and the PFC was predictive of behavioral control two years later, providing evidence that brain maturation can forecast future behavioral control. Knowing that brain development precedes behavior (Gabrieli et al., 2015); the foundation for adolescent behavior is thus laid during childhood. The studies in this thesis highlight the importance of incorporating childhood brain development in neuroscientific models by showing that the steepest increases in both behavioral control and subcortical-PFC structural connectivity take place during childhood.
Both empirical studies as well as theoretical models have mostly focused on developmental peaks in brain maturation (Casey et al., 2008; Galvan, 2010; Braams et al., 2015; Peters and Crone, 2017). Although this can be illuminating, I argue that the road towards this peak is more informative when it comes to development. The developmental phase that marks the steep increase preceding the peak is the time in which actual change is taking place. This could possibly
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